Both gorgeous names - personally I would go with Hector. Presumably both will go with the surname? I mean if your surname was House or something I'd go with Magnus. Similarly if your surname was Magnusson, I'd go with Hector.

Oh weird, I just came on to post a 'Magnus or ....' thread. Hector was on our list until I realised I couldn't tolerate the IL's H dropping to Ectah which made me think of ectoplasm! The verb wouldn't bother me at all.